scholarly journals Runoff, sediment transport, and water quality in a northern Illinois agricultural watershed before urban development, 1979-81

1984 ◽  
Keyword(s):  
Water Quality ◽  
Sediment Transport ◽  
Urban Development ◽  
Agricultural Watershed ◽  
Runoff Sediment

Long-Term (15 Years) Results of NPS Controls in an Agricultural Watershed upon a Receiving Lake's Water Quality

1993 ◽  
Vol 28 (3-5) ◽  
pp. 441-449 ◽  
Author(s):  
Paul J. Garrison ◽  
Timothy R. Asplund
Keyword(s):  
Water Quality ◽  
Structural Changes ◽  
Soil Phosphorus ◽  
Water Clarity ◽  
Management Control ◽  
Agricultural Watershed ◽  
Control Measures ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
White Clay

Nonpoint source controls were installed in a 1215 ha agricultural watershed in northeastern Wisconsin in the late 1970. Changes were made in handling of animal wastes and cropping practices to reduce runoff of sediment and nutrients. Modelling results predicted a reduction in phosphorus runoff of 30 percent. The water quality of White Clay Lake has worsened since the installation of NPS controls. The lake's phosphorus concentration has increased from a mean of 29 µg L−1 in the late 1970s to 44 µg L−1 in recent years. Water clarity has declined from 2.7 to 2.1 m and the mean summer chlorophyll levels have increased from 9 to 13 µg L−1 with peak values exceeding 40 µg L−1. Increased phosphorus loading is not the result of elevated precipitation but instead the failure of the control measures to sufficiently reduce P loading. Most of the effort was placed on structural changes while most of the P loading comes from cropland runoff. Further, soil phosphorus concentrations have increased because of artificial fertilizers and manure spreading. The White Clay Lake experience is discouraging since the majority of the polluters in this watershed utilized some NPS control practices, including 76 percent of the farms which installed waste management control facilities.

Sediment Transport and Water Quality Analyses of Naic River, Cavite, Philippines

2021 ◽  
Author(s):  
Cris Edward F. Monjardin ◽  
Raheemah A. Gomez ◽  
Marc Noblen G. Dela Cruz ◽  
Dennis Limher R. Capili ◽  
Fibor J. Tan ◽  
...  
Keyword(s):  
Water Quality ◽  
Sediment Transport

WATER QUALITY OF AN INTENSWE AGRICULTURAL WATERSHED IN QUEBEC

1998 ◽  
Vol 34 (2) ◽  
pp. 427-437 ◽  
Author(s):  
Paul Lapp ◽  
C. A. Madramootoo ◽  
P Enright ◽  
F Papineau ◽  
J. Perrone
Keyword(s):  
Water Quality ◽  
Agricultural Watershed

scholarly journals Effects of Spatial Scales on Runoff / Sediment Transport in Mountain Catchments (2) -Results from Intensively Studied Catchments

2018 ◽  
Vol 31 (4) ◽  
pp. 232-244
Author(s):  
Yuko ASANO ◽  
Taro UCHIDA ◽  
Masanori KATSUYAMA ◽  
Marino HIRAOKA ◽  
Shigeru MIZUGAKI ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Spatial Scales ◽  
Runoff Sediment

Large discrepancies on nitrate loading estimates from sparse measurements by SWAT and statistical models at catchment scale

2021 ◽  
Author(s):  
Kang Liang ◽  
Yefang Jiang ◽  
Fan-Rui Meng
Keyword(s):  
Water Quality ◽  
Agricultural Watershed ◽  
Data Availability ◽  
Accurate Estimation ◽  
Observation Data ◽  
Load Estimation ◽  
Concentration Data ◽  
Regression Methods ◽  
Nitrate Load ◽  
Sparse Measurements

<p>Nitrogen (N) is one of the major pollutants to aquatic ecosystems. One of the key steps for efficient N reduction management at watershed scale is accurate quantification of N load. High frequency monitoring of stream water N concentration has not been common, and this has largely been the limiting factor for accurate estimation of N loading worldwide. N loads have often been estimated from sparse measurements. The objective of this study was to investigate the performance of the physical-based SWAT (Soil and Water Assessment Tool) model and three commonly used regression methods, namely LI (linear interpolation), WRTDS (Weighted Regression on Time, Discharge, and Season), and the LOADEST (LOAD ESTimator) on estimating nitrate load from sparse measurements through a case study in an agricultural watershed in eastern Canada. The range of daily nitrate load of SWAT and LOADEST was 0.05-1.29 and 0.14 - 1.35 t day<sup>-1</sup>, compared with 0.13 - 13.08 t day<sup>-1  </sup>and 0.15 - 16.75 t day<sup>-1 </sup>for LI and WRTDS, respectively. Mean daily nitrate load estimated by the four methods followed the order: WRTDS > LI > LOADEST > SWAT. The large discrepancies were mainly occurred during the non-growing season during which there was observation data available. As regression methods use concentration data from dry seasons to estimate the concentrations of wet seasons, there is a strong likelihood of overestimation of nitrate load for wet seasons. The results of this study shed new light on nitrate load estimation under conditions of different data availability. Under situations of limited water quality measurement, policy makers or researchers are likely to benefit from using hydrological models such as SWAT for constituent load estimation. However, the selection of the most appropriate method for load estimation should be seen as a dynamic process, and case by case evaluation is required especially when only sparsely measured data is available. As agri-environmental water quality issues become more pressing, it is critical that data collection strategies that encompass seasonal variation in streamflow and nitrate concentration be employed in regions like Atlantic Canada in the future.</p>

Hydrodynamics, sediment transport, and water quality of two contrasting dredge pits on the Louisiana shelf

2021 ◽  
Vol 230 ◽  
pp. 104569
Author(s):  
Robert Bales ◽  
Kehui Xu ◽  
Guandong Li ◽  
Kanchan Maiti ◽  
Haoran Liu
Keyword(s):  
Water Quality ◽  
Sediment Transport ◽  
Louisiana Shelf
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